Apparatus and systems are known for clearing land mines. Commonly, land mine clearing apparatus is adapted for mounting on tracked vehicles which travel the ground to be cleared. Examples of such apparatus are described in U.S. Pat. No. 4,765,221 to Sombrowski, UK Patent Nos. 2,106,454 and 2,106,045, and German Patent DE 31 27 85 6 to Schaubele.
Pat. No. 4,765,221 describes an arrangement for receiving a clearing device having a rotatable tool for clearing land mines. The device can be pivoted through 90.degree. to facilitate transportation.
In the known prior art apparatus, during clearing, the clearing shaft is driven in rotation and the clearing tools attached to the shaft penetrate into the ground because of the high movement energy and throw the ground and any mines forward. The clearing shaft is generally supported on a frame to which it is connected by hydraulic units.
Clearing tools which rotate about the clearing shaft are generally hammer like elements which are rigidly attached to the shaft so as to provide sufficient force to clear the ground and the mines. Such rigidly fixed devices are likely to be easily shattered by the impact forces.
German Patent DE 31 27 85 6 to Schaubele describes clearing tools which consists of hammers which are pivotably attached to the clearing shaft to provide a certain degree of flexibility. UK Patent No. 2,106,045 describes land mine clearing apparatus which includes clearing shafts having impact elements secured by cables attached thereto to provide flexibility in one direction.
UK Patent No. 2,106,454 describes means for adjusting the height of the land mine clearing apparatus. These means comprise probe elements which are pivotably attached to the outer arms of the unit supporting the clearing shaft. The probe elements, which are in contact with the ground, send indications to a control device within the vehicle. The operator can then adjust the axis of tilt of the device accordingly.
The above referenced prior art devices though suitable for clearing land mines, are not normally suitable for general ground clearing of boulders and similar objects.